Objective:To investigate the protective effects of minocycline on renal ischemia-reperfusion injury and its mechanism in rats.Methods:72 male Sprague-Dawley rats were randomly divided into three groups:sham-operated(Sham)

ischemia-reperfusion(Ir)

minocycline hydrochloride(M)

for each of the four phases(6h、12h、24h、72h).45 minutes after the left renal artery occlusion on the basis of the right renal resection

we restored perfusion under modeling of ischemia-reperfusion injury.Determined myeloperoxidase(MPO)activity and serum creatinine(Scr)

which indicated the extent of the injury for neutrophil infiltration and renal function.Observed renal histological and ultrastructural changes.Results:The level of MPO and Scr was elevated in Ir

and it was distinctly lower in M than that in Ir.Difference between the two groups was of great significance(P<0.05

P<0.01).Pathological changes and ultrastructural lesion in renal tissue was identified morphologically and structurally after reperfusion

and significantly relieved in M.Conclusion:Minocycline has protective effects on renal ischemia-reperfusion injury in rats.